Hydraulic spike hammer or the like



Sept 10, 1968 H. J. MAISONNEUVE 3,400,769

HYDRAULIC SPIKE HAMMER OR THE LIKE 2 Sheets-Sheet l Filed March 2, 1966 NAW mw RMN wm. mm. Nm. mn.

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` HYDRAULIC SPIKE HAMMER 0R THE LIKE Filed March 2, 1966 2 Sheets-Sheet 2 United States Patent O 3,400,769 HYDRAULIC SPIKE HAMMER OR THE LIKE Hubert J. Maisonneuve, St. Laurent, Quebec, Canada, as-

signor to Canada Iron Foundries Limited, Montreal, Quebec, Canada, a company of Canada Filed Mar. 2, 1966, Ser. No. 531,203 Claims priority, applicatiolglanada, Mar. 8, 1965, 5 8 Claims. (Cl. 173-15) ABSTRACT OF THE DISCLOSURE A yhydraulic reciprocatory vibrator, espe-cially suited for spike drivers, has a ram reciprocable in a bore in a main housing and a spool of a shuttle valve reciprocable in a secondary housing. Pressurized hydraulic fluid is supplied through the shuttle valve into the bore to act on the ram to move it in each direction and, after substantial movement of the ram, to pass into the Shuttle valve to act on the spool to apply the pressurized fluid to the ram to reverse the direction of movement of the ram.

This invention relates to incompressible fluid reciprocatory devices and particularly to hydraulic uid hammers such as spike hammers.

Although the use of incompressible fluid in reciprocatory equipment is known and the possible advantages of such use have 'been realized, prior constructions have not been found commercially acceptable. An incompressible uid readily transfers energy and is a more eicient energy transfer medium than a `compressible fluid. Prior constructions have shown low efficiency, stall conditions during operation, and inability to withstand Continous use at the high energy transfer rates utilized by incompressible uid devices.

1t is an object of the present invention to provide an incompressible fluid reciprocatory device which overcornes the above disadvantages, which is efficient and is capable of continuous high energy transfer.

In accordance with the invention there is provided an incompressible fluid reciprocatory device comprising a main housing, a longitudinal bore in said housing, a ram slidably mounted in said bore for movement between a downstroke posiion and an upstroke position, said ram comprising a piston and two end portions fluid-tightly slidable in said bore and joined 'by stem portions with the piston intermediate the two end portions, the piston having a larger working area than the working area of one end portion and defining therewith and with the walls of the bore a first pressurizable chamber, the other end portion and the piston defining therebetween and with the walls of the bore an exhaust chamber, and the other end portion defining with the walls of the bore a second pressurizable chamber, each of said pressurizable chamber having an inlet port and an outlet port for pressurized fluid, each outlet port being located so as to be uncovered and included in its associated pressurizable chamber only on substantial travel of said ram, and the outlet ports communicating alternately with said exhaust chamber on the upstroke and downstroke of said ram respectively, a fluid control-valve having a bore with a spool reciprocable therein between two operative positions, supply means for pressurized incompressible hydraulic fluid connected to said control valve, the control valve in each of its two positions of the spool alternately connecting one of said inlet ports to the supply lmeans and the other to exhaust to recipro-cate the ram, said outlet ports being connected after said substantial travel to the control valve and operable on the spool to change the position of the spool when the inlet and outlet ports of one pressurizable 3,400,769 Patented Sept. 10, 1968 chamber are connected to the supply means and the outlet port of the other pressurizable chamber is connected to the exhaust chamber, whereupon the inlet port of the other chamber is connected to the supply means to reverse the direction of movement of the ram.

In a preferred embodiment of the present invention the fluid control valve comprises a valve housing having a valve bore extending longitudinally thereof, said bore having an inlet port for the introduction of hydraulic fluid under pressure, first pair of valve outlet ports spaced either side of said inlet port in fluid connection with the inlets of the main housing bore, and a second pair of valve outlet ports spaced either side of the first pair of valve outlet ports and connected to exhaust, a spool having a pair of spaced lands in slidable fit with the Walls of the valve bore, said spool being adapted to reciprocate be tween a first position in which one inlet of the main housing is in communication with the fluid pressure inlet, and the other in communication with exhaust, and a second position in which the connections are reversed, reciprocation of said spool in lbothl directions being etfected by hydraulic fluid pressure through the main housing bore outlets. While the above lluid control valve is preferred according to the present invention, it will be readily apparent that any other fluid control device which is actuated by the fluid existing from the main bore of the hammer and which responsive to this actuation reverses the flow of fluid under pressure to the ram in the main bore, will be Suitable for use with the hydraulic hammer of the present invention.

It will be readily `realized that in order to switch the hammer on and olf a stop valve is desirably provided and suitably this stop valve is actuated by contact of the striking end of the hammer with the object to be driven. Thus in a further embodiment of the present invention the fluid pressure inlet is controlled by a stop valve which comprises a valve housing a spool slida'ble in said housing between an open and closed position, said spool being biased into the closed position by a spring and actuated by a linkage, such as a rod, extending from the spool towards the striking end of said hammer such that Contact of said end with the object to be driven causes the rod to move` the spo-o1 to the open position: Suitably the rod extends between the spool and the anvil on contacting the object to be driven moves the spool to the open position.

The hammer of the present invention is admirably suited for driving any object into a substrate, such as the driving of spikes into railway ties for the location of railway lines. This type of hammer is generally referred to as a spike driver. It is generally desirable that the anvil is located in a sleeve which has the end thereof remote from the housing recessed to accommodate the head of the object to be driven, e.g. the spi-ke, and it is found normally that this end of the sleeve has also to be enlarged. By this means it is possible to determine precisely the depth to which the spike is to be driven into the tie by the relative depth of the recess with respect to the thickness of the head of the spike and the relative lengths of the sleeve and anvil. Thus when the recessed head of the sleeve comes into contact with the tie, the rod which opened the stop valve will automatically begin to move in the opposite direction and thus begin to close the stop valve, and when the anvil has reached its lowermost position in the sleeve the hammer will cease to function. Thus if the extension of the anvil in the lowermost position is less than that of the sleeve the depth to 'which the object is driven will be determined by the difference -in the extensions whereby over-driving of the object is avoided. Conversely the relative extensions of the anvil and sleeve are determined by '3 the use to which the hammer is to be put; in particular how -far the object is to be driven.

The yfollowing is a description by Way of example of an embodiment of the invention as applied to a hydraulic railroad spike driver, reference being had to the accompanying drawings, in which v FIGURE l is a longitudinal section of a hydraulic spike driver according to one embodiment of the present invention taken along the line 1-1 in FIGURE 2.

FIGURE 2 is a longitudinal section of the spike driver of FIGURE ltaken lalong the line 2-2 in FIGURE 1.

FIGURE 3 is a transverse section taken along line 3-3 in FIGURE 1.

FIGURE 4 is a transverse section taken along line 4-4 in FIGURE l.

FIGURE 5 is a transverse section taken along the lines 5-5 in FIGURE 1.

FIGURE 6 is a transverse section taken along the lines 6--6 in FIGURE 1.

FIGURE 7 is a transverse section taken along the line 7- 7 in FIGURE 1, and

FIGURES 8 and 9 are schematic views showin-g the hydraulic fluid connections between the spike driver housing and the hydraulic fluid control valve in the up-stroke and down-stroke positions of the ram.

With reference to the drawings, the spike-driver housing has a main bore therein to the upper end 21 of which hydraulic Huid is fed through a port 22. The main bore is reduced at 23 for a predetermined distance to form a cylinder Within the top 24 of piston-ram 25 reciprocates. The bore of the cylinder 23 is provided with a port 26 which is connected by a duct 27 to a cylindrical bore 28 formed in a block 29 of hydraulic iluid control valve 29a. The cylinder 23 is also provided with a second port 30 which is connected by a duct 31 to an exhaust port formed in the valve block 29. The diameter of the cylindrical bore 26 below the reduced portion 23 is enlanged to form a portion 32 `which slidingly receives a piston 33. The piston 33 operates the piston-ram 25 to its topmost (up-stroke) position and also acts during reciprocation within the bore 32 to seal off and open port 34 which is connected by duct 35 to a cylindrical bore 36. The piston 33 is joined to the top 24 by stem portions 33a and 33b. The lower portion 37 of the main bore is reduced in diameter and contains a piston rod 39 having an enlarged lower end 38. The lower end 37 of the main bore opens into a cavity 40 formed in guide-sleeve 41 which is secured to the lower end of the spike-driver housing 20. The lower end of the guide sleeve 41 is enlarged at 42 to accommodate the head of a railroad spike. Mounted within the bore of the sleeve 41 is an anvil 43 which in normal nonoperative position projects downwardly within the enlarged portion 42 of the sleeve 41 a distance determined by the thickness of the head of the spike and the depth to which it is desired to drive the spike.

The spike-driver is connected to a source of high pressure hydraulic fluid (2000 lbs/sq. in.) and a hydraulic fluid reservoir. The source of hydraulic uid, reservoir and spike driver may be mounted on a suitable railroad vehicle for track operation.

'When the spike-driver is placed upon the head of the spike to be driven the spike contacts the lower end of the anvil 43 projecting within the enlarged end 42 of the sleeve 41 forcing it upwardly until the top 44 of anvil 42, abuts the end of a rod 45 forcing it upwardly against a spool 46 of a master valve 47. The spool 46 shown in FIGURES 1, 8 and 9 is cylindrical in end elevation and is provided with a circumferential groove that permits an unobstructed flow, when the valve 47 is open, the hydraulic fluid from the inlet port 48 to the port 49, formed in the wall of cylinder S0 which is interconnected by a duct 51 to a port 52 formed in the cylindrical bore 53 of the control valve 29a. The spool 46 of valve 47 is provided within the bore 54 in which a compression spring 55 is seated, the free end of the spring bearing against the end of the bore 54 to bias the spool 46 towards closed position.

The spool 56 of the control valve 29a is relieved at its centre `and ends to provide liquid ow channels. The lands intermediate the centre and end portions acting to seal off and open ports 57, 58, 59 and 60 the port 57 being vented by an exhaustl duct 61 which is connected to a reservoir (not shown) and the port 58 connected by a duct `62 with port 22 -formed in chamber 21. When the mastervalve 47 and control valve 29a are in the positions shown in FIGURE 8 the high pressure hydraulic fluid exerts -a force upon end 24 driving the ram 25 downwardly (down-stroke) until it impinges against anvil 43 transmitting the force through the anvil 43 to the head of the spike. When the piston-ram 25 has essentially completed its down-stroke the port 26 is uncovered and the hydraulic Huid flows through duct 27 into cylindrical bore 28 and forces a member 63 downwardly thereby displacing spool 56 until it assumes the position shown in FIGURE 9. This movement of the spool 56 opens duct 31 and port 58 to exhaust duct 61 and diverts the high pressure fluid owing from master valve 47 through duct 5-1 into port 52 and thence through port 59 and duct 64 into port 65 formed in the wall of portion 32, 37 of the main bore. The portion 32 of the main bore being larger than portion 37 transmits a thrust on the lower surface of piston 33 forcing it upwardly effecting the 11p-stroke of the ram 25 the pressure of the fluid exerting a torce against the bottom of piston 33. The uid contained in chamber 21 upon upward movement of the piston-ram 25, i.e. the upstroke, is exhausted through port 22, duct 31, port 47 and duct 61 to the reservoir.

Just before completion of the up-stroke of the ram 25 the piston 33 uncovers port 34 whereby fluid passes from the port 65 to the duct 35 which builds up a pressure within cylindrical bore 36 and forces member 66 located therein to push spool 56 upwardly to assume the position, shown in FIGURE 8, which initiates the power downstroke herebefore described once again. When the spool 56 of the control valve 29a moves upwardly port 59 is vented to port `60 which is connected by duct 67 to exhaust duct 61.

The piston-ram 25 is slightly cushioned at the end of the up-stroke by a necked down portion 68 at the top of cylinder 32 and the lchamfered edge formed on the stem portion 33b of the ram 25- which in combination with the necked down portion 68 functions as a valve which automatically and progressively diminishes he ilow of the fluid trapped therein.

It `will be appreciated that the device according to the present invention could be used other than as a hammer, for example as a hydraulic vibrator. One such application of a vibrator could be for use with a drill bit for rock drilling while another application may be as a screen shadow.

What I claim as my invention is:

1. An incompressible uid reciprocatory device comprising a main housing, a longitudinal bore in said housing, a ram slidably mounted in said bore for movement between a downstroke position and an upstroke position, said ram comprising a piston and ltwo end portions Huidtightly slidable in said bore and joined by stem portions with the piston intermediate the two end portions, the piston having a larger working area than the working area of one end portion and dening therewith and with the walls of the bore a rst pressurizable chamber, the other end portion and the piston defining therebetween and with the walls of the bore an exhaust chamber, and the other end portion dening with the lwalls of the bore a second pressurizable chamber, each of said pressurizable charnbers having an inlet port and an outlet port for pressurized fluid, each outlet port being located so as to be uncovered and included in its associated pressurizable chamber only on substantial travel of said ram, and the outlet ports communicating alternately with said exhaust chamber on the upstroke and downstroke of said ram respectively, la duid control valve having a bore with a spool reciprocable therein between two operative positions, supply means for pressurized incompressible hydraulic fluid connected to said control valve, the control valve in each of its two positions of the Spool alternately connecting one of said inlet ports to the supply means and the other to exhaust to reciprocate the ram, said outlet ports being connected after said substantial travel to the control valve and operable on the spool to change the position of the spool when the inlet and outlet ports of one pressurizable chamber are connected to the supply means and the outlet port of the other pressurizable chamber is connected to the exhaust chamber, whereupon the inlet port of the other chamber is connected to the supply means to reverse the direction of movement of the ram.

2. A device according to claim 1 wherein said outlet ports are alternately connected to said supply means on substantial completion of the stroke of the ram in each direction.

3. A device according to claim 1 in which on the downstroke of the ram the inlet and outlet ports of one chamber are connected to the supply means on completion of the stroke and on the upstro'ke of the ram the inlet and outlet ports of the other chamber are connected to the supply means before the completion of the stroke, whereby pressurized iluid is supplied to the said one chamber to decelerate the ram on its upstroke.

4. A device as claimed in claim 3 in which an anvil is located for reciprocation beneath the ram and is struck thereby when the ram reaches it downstroke position.

5. A device as claimed in claim 4 in which the anvil is disposed in a sleeve which has the end thereof remote from the housing recessed to accommodate the head of the object to be driven.

6. A device as claimed in claim 5 in which the lengths of the anvil and sleeve are such that the extension of the anvil in -its lowermost position is less than the extension of the sleeve whereby to prevent over-driving of the object to be driven.

7. A device as claimed in claim 1 in which the fluid control valve comprises a valve housing having a valve bore extending longitudinally thereof, said bore having an inlet port for the introduction of hydraulic fluid under pressure, a rst pair of valve outlet ports spaced either side of said inlet port in uid connection with the inlet ports o f said main housing bore, and a second pair of valve outlet ports spaced either side of said first pair of valve outlet ports and connected to exhaust, a spool having a pair of spaced lands in slidable fit with the `walls of the valve bore, said spool being adapted to reciprocate between a rst position in which one inlet port of the main housing is in communication with the uid pressure inlet port and the other in communication with exhaust and a second position in which the connections are reversed, reciprocation of said spool in both directions being eiiected by hydraulic tluid pressure through the main housing bore outlet ports.

v8. A device as claimed in claim 7 in which the fluid pressure inlet port is controlled by a stop-valve which comprises a valve housing, a spool slidable in said housing between an open and closed position, said spool being biassed in the closed position by a spring and actuated by a rod extending from said spool towards the striking end of said hammer such that contact of said end with the object to be driven causes the rod to move said spool to the open position.

References Cited UNITED STATES PATENTS 964,970 7/ 1910 Hultquist 91--290 1,102,271 7/1914 Hunter 173-15 1,429,786 `9/1922 Smith 173-134 1,740,713 12/1929 Rundqvist 91-290 1,846,804 2/1932 Hansen 173--135 1,922,329 8/1933 Richardson 173--134 2,372,029 3/1945 Stair 173-133 2,380,315 7/1945 Kilian 91-290 2,547,224 4/1951 MacGuire 173--15 2,919,678 1/ 1960 Sublett et al l73l33 JAzMES A. LEPPINK, Primary Examiner. 

